In situ observation of concentrational stratification and solid-liquid interface morphology during Ga-5% In alloy melt solidification

Segregation of indium during solidification of a Ga-5 wt% In alloy melt was investigated with in situ real-time X-ray density visualization under vari ous solidification conditions. Indium stratification in the melt was observ ed at the very beginning of solidification. Substantial indium stratificati on developed even with convective flow in the melt. The solid-liquid interf ace morphology was found to be strongly dependent on the chemical stratific ation in the melt and the hydrodynamic state (convective or conductive). On the other hand, the interface morphology development was found to affect ( decelerate or accelerate) the indium stratification by influencing the conv ection pattern in the melt. (C) 1999 Elsevier Science B.V. All rights reser ved.